It's almost that time of year where I'm gonna need HEAT

ChrisMc

ChrisMc

Well-Known Member
Joined
Aug 11, 2009
Location
Holly Springs, NC
1999 Jeep Cherokee 4.0l

For the past couple years it really hasn't had heat or ac. I flushed and back flushed the heater core with the water hose and got a gallon of brown water out. Luckily there's no water on the floorboard so more than likely the heater core isn't cracked. The air is somewhat warm but no where near where it should be. I'm gonna do a complete system flush but is there anything I could be missing?
 
No expert & there has been similar post on here; the XJ gurus will jump in here. Generally it gets to disconnecting the heater hoses, & checking with a water hose, to verify the flow of the heater core. Then, is the thermostat letting the engine heat up to 180/190F? There are heater box controls, that open & regulate doors to let heat into the cabin. Some vehicles even have problems with the heater core being mounted higher than the radiator, & sir pockets keep the core from getting proper water flow.
 
Blend door.
Just a guess.
 
It blows out all of the vents relatively hard. I can cycle through all the settings. My switch is just broken so it only works on the highest setting. Water flows both ways through the heater core. Ill probably do a water pump and a thermostat soon cause the jeep has 215k on it and I dont believe they have been done
 
If the air blows hard but isnt warm and the heater core flows good, it re-affirms my statement of a blend door.

Its job is to regulate how much outside (cold) air is mixed with treated air (eaither across the heater core or across the A/C coil).

Its known to get out of sync or flat out break and cause a constant over mix of outside air.
 
You said your heat blows pretty hard, but doesnt work on any thing but high. I had the same problem and thought my switch was broke to. Changed the blower motor and that fixed. If you've never changed it you might consider changing it. They are pretty cheap and easy to get to
 
Loganwayne said:
You said your heat blows pretty hard, but doesnt work on any thing but high. I had the same problem and thought my switch was broke to. Changed the blower motor and that fixed. If you've never changed it you might consider changing it. They are pretty cheap and easy to get to
Click to expand...
Er? Wouldn't That be the rheostat, or is it somehow built into the blower motor?
 
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